Infectious disease - TB and Hepatitis Flashcards
Infectious disease - definition
Clinically evident infection causing injury and clinical signs/symptoms
“communicable disease” definition
is one in which the pathogen may be transmitted from one person to another
Hepatitis is what
inflammation of the liver
most common cause of infectious hep in US is viral
significant amounts are unreported
Non-infectious hep aka
Nonviral
Non-infectious hep causes
Medication overdose - acetominophen, niacin
Toxins - carbon tetrachloride (freon)
Autoimmune disorder - multisystemic disease
Viral hepatitis description
6 strains of viruses have been identified 3 of most common are - Hep A (infectious) - Hep B (serum) - Hep C (non A, non B)
Hep A - chronic infection
NO - it does not have a chronic infection component to it
Hep B - chronic infection
YES
Hep C - chronic infection
YES
Hep A - how transmitted
feces, bile, blood, shellfish
ORAL - FECAL route of transmission
person to person contact
Hep A - incubation
30-45 days
Incubation means you are infected and can spread during this time
Hep A - onset
acute with fever
Hep A - contagious for how long
up to 3 months after onset of s/s
Hep A - prevention/treatment
Pre/post immunization
Hygiene
Hep A - mortality
Mortality rate is low - if do pass away, is likely due to something else going on
Hep B - how tranmitted
Blood, body fluids, contaminated needles
Often sexually transmitted
Hep B - incubation
60-180 days
Hep B - onset
insidious - often don’t know they are sick until months into the disease
Hep B - chronic
yes
up to 30% develop chronic hepatits
Hep B - prevention/treatment
pre-post immunization
interferon, antiviral meds
Hep B - mortality
1% develop fulminant hepatic failure with an 80% mortality rate!!!
Hep C - transmitted how
Most cases of transfusion hepatitis
Blood, infected needles
Hep C - Incubation
30-180 days
Hep C - onset
insidious
Hep C - chronic
Yes!
up to 50-80% develop chronic hepatitis
Hep C - prevention/treatment
screening, modify risk bx
No immunizations for this!
Clinical presentation - ranges from
absence of s/s to liver failure and then coma and death
Clinical presentation - phase 1
incubation - hepatitis virus in stool
Clinical presentation - phase 2
prodromal - when people usually seek doctor
Fatigue, anorexia, malaise, vomit, HA, cough, low fever, weight loss, abdominal pain
Often misdiagnosed with gastroenteritis!!!
Clinical presentation - phase 3
Icteric (acute)
Jaundince, dark urine, discolored stool, hepatomegaly, tender liver, abdominal pain
Clinical presentation - phase 4
recovery - resolution of jaundice, symptoms diminish, liver may stay enlarged
Liver will not shrink back to normal!
Complication - Fulminant hepatitis is what
CLinical syndrome with necrosis of liver cells
jaundice, abdominal pain, anorexia, vomit are initial signs
ascites and GI bleed in later stages
Complication - fulminant hepatitis - what is the outcome
necrosis of the liver is irreversible
up to 90% of patients die
need liver transplant!!!
Cirrhosis is what
irreversible inflammation causing fibrosis
Development of cirrhosis
multiple causes
liver hypertension occurs at end stage
often develops slowly but if toxins are involved it can progress quickly
Cirrhosis - effect on other systems
Hormone effects
Metabolism effects
Portal hypertension effects
Cirrhosis - effect on other systems - hormone
menstrual dysfunction
hair loss
spider angiomas
edema
Cirrhosis - effect on other systems - metabolism
jaundice light colored stool bleeding tendency dark urine hypoglycemia
Cirrhosis - effect on other systems - portal hypertension effects
Ascites in the abdomen edema anemia leukopenia internal varices
Treatment summary for hepatitis
IMMUNIZATION for A and B
Supportive tx
Watch for complications
Chronic hepatitis - goal of tx is to
reduce liver inflammation and scarring
TB - timeline
1865 - contagious 1882 - organism discovered 1884 - first sanatorium in US 1943 - drug discovered to tx (streptomycin) 1970 - sanatoriums closed 1980 - rise of TB cases (mid 1980s) 1993 - decline in TB
TB - overtime what has happened
overall decline but recent increase in the drug resistant TB
higher rates in port states
TB - demographics
most 24-63 yrs of age
M more than F
TB - causative pathogen
In US majority are by mycobacterium tuberculosis
TB - infectious process - how spread
it is spread through the air
infection occurs when susceptible person inhales droplet nuclei containing tubercle bacilli and the droplet nuclei reaches the alveoli in the lungs
Immune response can kill most bacilli, leading to formation of a granuloma
Latent TB
Not active disease
Granuloma has been established
Immune response controlled the infection
Tests pos on the skin test (but they dont have disease and cant spread it)
Active disease - TB
Can be soon after infection or years later
5% who are infected will develop the disease within 1-2 yrs of the infection
Another 5% will develop it sometime later
Inc rate in those with dec immune response (ex - those with HIV)
TB infection vs. TB disease - for both of them
Tubercle bacilli in the body
Tubercle skin test usually positive
TB infection vs. TB disease - chest x ray
infection - normal
disease - abnormal
TB infection vs. TB disease - sputum smears and cultures
infection - negative
disease - positive
TB infection vs. TB disease - symptoms
infection - none
disease - cough, fever, weight loss
TB infection vs. TB disease - infectious
infection - not infectious
disease - often infectious before tx
TB infection vs. TB disease - case of TB?
infection - no
disease - yes and should be reported
TB classification system
0 - no exposure, not infected 1 - exposure yes, no evidence of infection 2- infection yes, no disease 3 - TB case, clinically active 4 - TB case, not clinically active 5 - TB suspected
Risk factors for TB infection
Foreign born Travel Urban poor, homeless Military personnel Illicit drug use - injected Health care workers
Risk factors for TB disease
HIV infection Recent TB infection DM Sillicosis Prolonged corticosteroid use Immunosuppresive therapy Cancer Severe kidney dsease Intestinal conditions Low body weight
TB clinical manifestations
Cough with duration 3 weeks or more
Chest pain
Hemoptysis
Systemic s/s - fever, chills, night sweats, appetite loss, weight loss, easy fatigability
TB - Extrapulmonary TB
common site - skeletal system - common is spine (Potts)
also now finding it in TMJ
TB intervention
PREVENTION!
long term tx (3-12 months)
Multiple drugs
Directly observed therapy (DOT) preferred management strategy
TB goals of tx
Cure pt, minimize death and disability from TB
Interrupt transmission to other people
TB - drug therapy includes
Multidrug! First line = - isoniazid (INH) - Rifampin (RIF) - Ethambutol
Now seeing Pyrazinamide (PZA) for the drug resistant strain of TB
